1. Field of the Invention
This invention relates to methods of processing chocolates and products produced using the same. More specifically, the invention relates to methods of processing tempered chocolates at higher temperatures and/or without the detrimental increases in apparent viscosity typically associated with the processing of tempered chocolates. In addition, the invention relates to improved products made according to the processing method.
2. Description of the Related Art
Documents and references which pertain to the field of this invention or are otherwise relevant to the practice of the invention are cited in this disclosure with a full citation for each. Each citation is hereby incorporated by reference.
Chocolate confection have a very distinct taste and mouthfeel that have been enjoyed by individuals for many years. The unique flavor and mouthfeel of chocolate is a result of the combinations of its numerous components as well as its process of manufacture.
Chocolate contains solids particles dispersed throughout a fat matrix. The term xe2x80x9cfatxe2x80x9d includes, for example, cocoa butter and milk fat. Similarly, chocolate-like compositions may also contain fats other than, or in combination with, cocoa butter. Accordingly, melted chocolate and chocolate-like compositions are suspensions of non-fat particles, e.g., sugar, milk powders and cocoa solids, in a continuous liquid fat phase. The fat phase of milk chocolate, for example, is typically a mixture of cocoa butter, a suitable emulsifier and milk fat with cocoa butter being typically the predominant fat in the chocolate.
Cocoa butter is solid at room temperature (21xc2x0-24xc2x0 C.). Accordingly, chocolate is firm and solid at room temperature thereby providing good xe2x80x9csnapxe2x80x9d at initial bite as well as resistance to deformation and/or surface marking. Above room temperature, the fat phase melts progressively until completely melted at about 36xc2x0 C. Therefore, chocolate is typically fully melted at body temperature (about 37xc2x0 C.). This rapid melting in the mouth at the body temperature provides the smooth, creamy mouthfeel which results in a strong flavor impact.
Cocoa butter, however, is a polymorphic material in that it has the ability to crystallize in a number of different crystal packing configurations (Wille and Lutton, xe2x80x9cPolymorphism of Cocoa Butterxe2x80x9d, J. Am. Oil Chem. Soc., Vol. 43 (1966) pages 491-96). Six different polymorphic forms are generally recognized for cocoa butter. Forms I and II are produced, for example, by rapidly cooling melted untempered chocolate to low temperatures and are very unstable and have a lower melting point. Forms III and IV melt at higher temperatures than Forms I and II but are not the most desirous forms for confectionery manufacture. Forms V and VI are the most stable forms of cocoa butter. It is desirable to have Form V as the predominant form in a well-tempered chocolate. Form V may transform slowly into Form VI after a period of time. Accordingly, chocolate processing is strongly linked to the crystallization and polymorphic behavior of the fat phase. Before chocolate can be satisfactorily processed from liquid to finished solid confection using conventional methods, it must be tempered after which it is gently cooled in order to form a set chocolate having a stable fat phase.
Before the development of tempering machines, this process was carried out by pouring the chocolate onto a marble slab and working it with a flexible spatula until it began to thicken. At this point both stable and unstable polymorphic forms were crystallized, and the thick xe2x80x9cmushxe2x80x9d was mixed into a bowl of warm chocolate to melt out the unstable crystals prior to use. At this stage the chocolate was tempered.
The most commonly used method for currently tempering chocolate typically involves the following sequential steps:
A. complete melting of the chocolate fat phase;
B. cooling to the point of initial crystallization of the fat phase (i.e., below the melting point of the liquid fat phase);
C. crystallizing a portion of the liquid fat phase to form stable and unstable fat crystals;
D. slight heating to melt out any unstable crystals that may have formed leaving from about 3 to 8 wt % as seeds for crystallizing the remaining liquid fat; and
E. cooling to set the chocolate, typically in a cooling tunnel.
Accordingly, during conventional chocolate processing, the chocolate mixture is initially melted at temperatures of about 45xc2x0 C. and tempered by cooling with agitation to about 29 to 30xc2x0 C. The precise temperature-time profiles used when tempering a chocolate will vary depending on the recipe of the formulation, the tempering equipment and even the purpose for which the chocolate will be used. The tempering of the chocolate results in a chocolate dispersion having fat crystals dispersed throughout the liquid fat phase. The chocolate suspension may then be further processed prior to solidification, for example, by enrobing the chocolate onto an edible center or molding the chocolate into a shape or form. The chocolate is finally set into a sufficiently solid form for wrapping by gentle, controlled cooling.
Conventional tempering therefore is the controlled partial precrystallization of the fat phase which is believed to be necessary to produce a stable solid form of the fat in the finished product. It is an important object of tempering to develop a sufficient number of stable fat crystals so that under appropriate cooling conditions the fat phase of the chocolate is able to crystallize into a stable polymorphic form. Accordingly, the purpose of tempering is to ensure that the cocoa butter crystallizes in a stable form.
Since melted chocolate is a suspension of solid particles, e.g., sugar, milk powders and cocoa solids, in a continuous liquid fat phase of cocoa butter, chocolate suspensions have non-Newtonian flow behavior including the presence of a yield stress. The yield stress represents a minimum threshold of force that must be applied to a suspension, for example the force applied to toothpaste, in order to make it flow. Below this threshold, no flow occurs. The non-Newtonian behavior of chocolate is sometimes described by fitting the rheological data to the Casson equation which defines a Casson yield value and Casson plastic viscosity. This minimum force mentioned above is then referred to as the xe2x80x9cCasson yield valuexe2x80x9d. The xe2x80x9cCasson plastic viscosityxe2x80x9d approximates the work done to keep the suspension flowing uniformly. Alternatively, an apparent viscosity can be used to describe the flow behavior of chocolate.
A variety of factors influence the flow properties or the rheological behavior of chocolates. These factors include fat content, emulsifier content, moisture content, particle size distributions, particle shapes, temperature, conching conditions, including time and temperature of conching, and temper level.
To provide good flow properties, every particle dispersed in the chocolate suspension should be coated with fat. It is important that fat covers the surface of all or substantially all the solid particles to minimize the particle-particle interactions which reduce flow. Accordingly, the amount of flowing liquid phase in the suspension in relation to the amount of solid is a significant factor which influences the rheology of a suspension.
The rheological behavior of chocolate is important for manufacturing. Previous methods of maintaining a controlled viscosity during processing rely on careful control of the temperature of the chocolate as well as temper level. Many applications for chocolates require careful control of rheology. One example of such an application is xe2x80x9cenrobingxe2x80x9d, the process of coating chocolate onto an edible center. Enrobing is accomplished when the chocolate is in a fluid-like state. Since enrobing is a coating application, it requires good flow properties to provide a high quality coating layer. For enrobing, proper yield value and viscosity must be maintained in order to produce a satisfactory coated product. Uncontrolled viscosity changes of an enrobing chocolate can be the cause of numerous processing problems. Poor flow properties may result in an improper or unsatisfactory coating of the food center which may result in product defects such as (a) the food center showing through the coating due to an uneven coating, (b) pits in the coating resulting from the fracture of air bubbles trapped while enrobing, (c) xe2x80x9cwide feetxe2x80x9d due to excess chocolate forming ridges at the edge surrounding the bottom portion of the product and (d) cracking. Such defects can result in the edible center drying out or becoming detrimentally oxidized. Furthermore, some defects result in flakes or chips of the solidified chocolate coating eventually fracturing off the product resulting in a chocolate product having a reduced coated weight of chocolate. These defects are discussed further below in relation to FIG. 16.
Moreover, if the viscosity of the chocolate increases too much while in the enrober or any other apparatus, it can become too thick for flow and cause solid chocolate build-up on enrober surfaces, and/or even xe2x80x9cfreezexe2x80x9d the enrober or any other apparatus. Alternatively, the temperature of the tempered chocolate may get too high, melting out any seed crystals in the composition and thus, resulting in a loss of temper. If the temper of the enrobing chocolate is lost through the melting of the seed crystals, the resultant coating will have poor qualities such as low resistance to fat bloom and potentially poor gloss.
As set forth above, the fat content of a chocolate composition influences the rheological properties of the composition. Decreasing the fat content will increase the viscosity all other factors being the same. A variety of methods have been developed to try to reduce the fat content in chocolate without increasing the viscosity of the chocolate to the point that it cannot by processed. Such methods for reducing the viscosity in chocolate formulations appear to focus on the non-fat particle/liquid interactions within the suspensions. These methods require the control of solid particle sizes, moisture level, fat absorption into the particles, surface characteristics of the particles, etc. Each of these factors are directed to reducing the amount of fat necessary to lubricate the chocolate suspension and provide good rheological properties. (See Industrial Chocolate Manufacture and Use, Second Ed., Edited by S. T. Beckett, article entitled xe2x80x9cChocolate Flow Propertiesxe2x80x9d by J. Chevalley, at page 146; and an articles entitled xe2x80x9cInfluencing the Rheological Behavior of Chocolate Massxe2x80x9d by Dr. S. T. Beckett, presented at Penn. Manufacturing Confectioners"" Assn., Volume XVI, No. 1, April. 1992).
U.S. Pat. No. 5,464,649 to St. John et al. relates to reduced fat chocolates having Theological flow properties associated with normal fat content chocolate. The patent discloses maintaining acceptable flow properties by controlling the surface area of the non-fat solid particles, reducing the absorption of liquid fat into these particles and decreasing the interactions between these particles.
It is well-known that increasing the surface area of the particles in a chocolate suspension increases the amount of liquid fat needed to maintain the same viscosity. Therefore, providing smoother or rounder particles decreases the amount of liquid fat necessary to maintain any given level of viscosity. Also, the absorption of liquid fat into the solid particles decreases the amount of liquid fat available for lubricating the suspension thereby also increasing viscosity. U.S. Pat. No. 5,464,649 relates to modifying the non-fat solids/liquid fat interactions of the chocolate suspension.
Temper level is an important factor that influences the viscosity of chocolate. As set forth above, the development of xe2x80x9ctemperxe2x80x9d is a prerequisite for the production of good quality chocolate and is defined as the creation of stable cocoa butter seed crystals in the chocolate.
It is well-known that the viscosity of a suspension increases with decreasing liquid phase (Industrial Chocolate Manufacture and Use, Second Ed., Edited by S. T. Beckett, Article entitled xe2x80x9cChocolate Flow Propertiesxe2x80x9d by J. Chevalley, at page 146). Moreover, viscosity is also increased by decreasing the temperature of a fluid suspension. That is, the viscosity of fluid suspensions decrease with increasing temperature.
Accordingly, increases in viscosity occur during conventional tempering since temper is induced by the partial pre-crystallization of cocoa butter through cooling. As a result of tempering, the amount of liquid phase is decreased as it partially solidifies and the amount of solid particles is increased, and, as a result, the viscosity is increased. The onset of pre-crystallization and the consequent increase in viscosity occurs when the melted chocolate is cooled to a temperature below the crystallization temperature of the liquid fat phase. The crystallization gradually continues until the chocolate is ultimately set by cooling. During tempering, a percentage of the liquid fat becomes solid, believed to be in the range of 3-8%. This results in an increase in viscosity since the amount of liquid phase is reduced and the amount of solid phase increased at the same time. FIG. 3 illustrates the viscosity increase that occurs during conventional tempering processes. Finally, to avoid melting out the cocoa butter seed crystals, tempered chocolate must be held at a lower temperature, e.g., 29-31xc2x0 C., and this also increases viscosity. It is the combination of these factors which causes the viscosity to rise so dramatically during conventional chocolate tempering. As a result, higher levels of fat are necessary to ensure the viscosity of the chocolate does not progress beyond the point which renders the chocolate unworkable.
Moreover, since the chocolate suspension must be cooled for tempering, the viscosity also increases due to the lower temperatures. Accordingly, not only does tempering result in a change in rheology due to the formation of fat crystals at the expense of the liquid lubricating phase, but the rheology is also adversely affected by the low temperature used to induce and maintain an acceptable temper level.
U.S. Pat. No. 5,464,649 and the other cited references do not address the viscosity increases that result during conventional processing, particularly from tempering. In fact, the patent only discusses Casson yield and Casson plastic viscosity values taken at 40xc2x0 C. for the rheological values of the chocolate formulations, i.e. when the fat phase is in a fully liquid state. Unfortunately, the control of the rheological properties of a fully melted chocolate, although well-known as being beneficial in improving the flow properties of the chocolate when being processed, only adjusts the starting point at which the viscosity will begin to increase during tempering. Such methods do not avoid or reduce the substantial viscosity increase typically encountered during the tempering of chocolates.
Moreover, since conventional tempering results in an increase in viscosity, the initial viscosity of the chocolate composition before tempering, the Casson plastic viscosity value for example, must be low enough to take into account the viscosity increases that occur during the tempering process. Otherwise, the tempered chocolate will thicken during tempering past the point where it can be used in processes such as enrobing, etc. During conventional tempering processes, since the chocolatier anticipates taking a substantial viscosity increase during tempering, the chocolate formulated must have a good initial viscosity.
Accordingly, the viscosity increases during conventional tempering result from the formation of seed crystals which increase the solid load, i.e., solid phase volume, of the chocolate. Moreover, the seed crystals are formed at the expense of the liquid fat which is the source of chocolate lubricity.
As discussed above, after the tempering is initiated using conventional methods, it becomes more and more difficult to pump the chocolate through processing apparatuses and mold into shapes or enrobe onto edible products. That is, once tempering is initiated, the viscosity of the chocolate increases making it more difficult to work. Furthermore, the increased viscosity of the chocolate makes it more difficult to form a high quality molded or enrobed product. If the chocolate is too thick, the molded products will typically contain air bubbles since they are unable to escape. Conversely, if chocolate having uncontrolled rheological variations is used for enrobing purposes, the enrobed product may be too thin, too thick and/or uneven. For example, when enrobing, the temper/viscosity is often adjusted to obtain the correct weight on the enrobed product. If the chocolate is too thick, the temperature of the composition must be increased to reduce viscosity, However, this may also decrease the temper. This results in longer cooling times and increases the chocolate susceptibility to bloom. (Pennsylvania Manufacturing Confectioners Association: Research Notes, Volume XVI, No. 1, April 1992, xe2x80x9cInfluencing the Rheological Behavior of Chocolate Massxe2x80x9d by Dr. S. T. Beckett).
The following references relate to the state of the art.
U.S. Pat. No. 4,446,166 to Giddey et al. relates to a heat-resistant chocolate article comprising a chocolate mass containing cocoa butter, sugar, milk solids and cocoa solids and, dispersed throughout the mass about 2 to 10 percent by weight of a water-in-fat emulsion, at least a portion of the fat being in solid form.
U.S. Pat. No. 4,910,037 to Sagi et al. relates to powdery tempering accelerators useful for omitting or simplifying the tempering operation in the production of oily compositions such as chocolate and a method of using the same. The tempering accelerators comprise a fat or oil containing a 1,3-saturated-2-unsaturated triglyceride. The accelerator can be prepared from a natural fat or oil such as cacao butter, mowrah butter, illipe butter, etc. The crystal is preferably Form V or more stable forms of cocoa butter. The powder particles can be obtained by spraying or pulverizing the solid fat under a low temperature atmosphere. An accelerator is added to the oily composition as the composition is solidified by cooling. The accelerators disclosed in the patent are intended to xe2x80x9crapidlyxe2x80x9d form stable crystals in the chocolate and are added to initiate and/or accelerate the solidification of the liquid fat phase in the chocolate composition.
U.S. Pat. No. 5,108,769 to Kincs relates to a fat component for confectionery coatings comprising a structured fat emulsion which can be incorporated directly into a confectionery coating composition when it is formulated and which will not thicken or set up until it passes through a cooling tunnel. The structured fat emulsion also raises the heat set properties of the confectionery coating in order to provide a finished product which exhibits the good eating quality of a low melt point fat, but enhanced heat resistance at normal temperatures. The fat component is a structured fat emulsion in which a polyol is emulsified and encapsulated into a partially hydrogenated fat.
The above-described methods fail to disclose methods which allow for the control of the rheological properties of chocolate formulations during tempering and/or the use of elevated temperatures during tempering. It would be highly advantageous to provide methods of tempering chocolates which allow for greater flexibility during processing while at the same time avoiding the careful temperature and temper level controls typically required during chocolate processing. Such methods would also reduce or eliminate the detrimental increases in viscosity that occur in conventional processing. Providing such methods would not only allow for easier, more flexible and more efficient methods of manufacture, but would also enable the development of new and advantageous method and product designs which would permit the use of previously unsuitable chocolate formulations, such as low fat formulations, in a greater variety chocolate applications.
It is an object of the invention to overcome the above-described difficulties in the related art.
It is another object of the invention to provide a method of processing chocolate compositions having a temperable fat phase without the detrimental increases in viscosity typically encountered with conventional chocolate processes.
It is still a further object of the invention to provide a method of processing chocolate compositions at elevated temperatures.
It is yet another object of the invention to provide a method of enrobing or molding or otherwise processing chocolate compositions having lower viscosities, particularly low fat formulations.
The foregoing and other objects and advantages of the invention will be set forth in or be apparent from the following description.
The present invention relates to improved methods of making chocolates that minimize the dramatic increases in viscosity typically associated with tempered chocolate. The invention also relates to the ability to process chocolates at higher temperatures without the need to temper at low temperatures.
One aspect of the invention relates to the use of seeding agents to provide temper without initiating the crystallization of the liquid fat phase that occurs during conventional tempering. Preferably, the use of seeding agents according to the invention actually postpones the crystallization of the fat phase. This enables the seeded chocolate to be used in a variety applications that require low viscosities, such as enrobing. The use of the seeded compositions in such applications allows for the manufacture of high quality products such as enrobed products having more uniform coatings with lower fat contents.
Another aspect of the invention relates to methods of maintaining seeded compositions at elevated temperatures without losing the temper induced by the addition of the seeding agents. If the temperature of the seeded composition is not brought below the solidification temperature of the fat phase, as in traditional tempering methods, the increase in viscosity due to cooling and/or maintaining the formulation at lower temperatures is avoided. Processing the seeded chocolate at higher temperatures also lowers the tempered chocolate viscosity. The seeded compositions can be maintained at higher temperatures as long as the processing temperatures are below the melting temperature of the seeding agent. As a result of the ability to process the seeded compositions at elevated temperatures, the chocolate can be further processed with an even lower viscosity value for any given chocolate formulation. After the further processing, i.e., enrobing, injection molding, etc., the chocolate is then solidified in a cooling apparatus as in normal chocolate processing.
The presently disclosed processes also result in reduced chocolate build-up problems in enrobers or other apparatus since the continual increase in viscosity during conventional tempering is avoided. The increase in viscosity results in the chocolate becoming increasingly difficult to work with as the tempering progresses.
Yet another aspect of the invention relates to methods of using seeding agents to introduce a controlled targeted level of temper in a chocolate composition at the low or ultra-low temper range. Since the additional tempering of the chocolate through crystal formation and/or crystal grain growth is postponed by maintaining the temperature of the seeded composition above the solidification temperature of the liquid phase, the amount of temper in the formulation is controlled by varying the amount of seeding agent added. This enables the formation of a wide range of temper levels including low temper and ultra low temper. Such chocolate formations can provide highly advantageous results when used in combination with rapid cooling processes such as even lower fat formulations.
A still further aspect of the invention relates to seeded chocolate formulations made according to the present invention having improved wetting characteristics and lower viscosity providing for thinner, more uniform coatings, improved injection molding, shell molding, tablet molding, introduction of tempered chocolate into panning processes, enhanced spin molding performance and broader product design options.